Process of manufacturing asphalt.



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REINHOLD WALLBAUM, OF SUDENDE, NEAR BERLIN, GERMANY.

PROCESS OF MANUFACTURING ASPHALT.

Ho Drawing.

To all 10710222 itmay concern:

Be it known that I. Dr. REIXHOLD VALL- BAL'M, a German subject, residingat 13 Mittelstrtrsse. Siidende, near Berlin, Germany, have invented anew and useful Improved Process of Manufacturing Asphalt. of which thefollowing is a specification.

Asphalt powder for producing compressed asphalt has hitherto been madefrom the bituminous lime-stone present in nature, such lime-stonegetting pulverized and then dried. The freight which is to be paid alsofor the filling. material highly raises the price of such asphalt. Ithas therefore been attempted to manufacture artificial asphalt of thiskind by impregnating dust-like filling-materials, such. for instance, asground lime-stone, with asphalt-bitumen. By this means. however, asatisfactory result is not obtained. because it is impossible to causethe asphalt to be distributed in the filling-material equally.

According to my invention the dust-like filling material is mixed withan aqueous emulsion of asphalt, of the kind set forth in my BritishPatents No. 28,178 of 1910 and No. 23,468 of 1911. This permits of asimple, safe working. The filling material is preferably moistened tosome extent and then kneaded after the emulsion of asphalt has beenadded, The filling-materials employed may consist of dust-like productssomewhat capable of absorbing liquid, such, for example, as lime-stone,whiting or Spanish white, silicious lime-stone, trass,

and dust-like chippings of stone-pits. Also natural asphalt-powder forproducing compressed asphalt may be mixed with such emulsion and thuseasily be made, to contain Specification of Letters Patent.

Patented Mar. 21. 1916.

Application filed November 12, 1913. Serial No. 800,675.

a certain amount of asphalt. One can also proceed in such a way that theemulsion of asphalt, sufliciently diluted. is poured on the dryfilling-material. The kneaded, thoroughly-mixed mass thus produced isthen completely dried; small lumps which may be formed by the drying canbe easily crushed and will fall to pieces on temperature rising. In thisway a dark-brown powder is obtained in which the asphalt is.

contained in a finest equal distribution and which does not differ fromthe natural asphalt, designated to be compressed, as to appearance andproperties.

The productis employed in the same manner as natural asphalt-powder;after having been heated it can be compressed by ramming or rolling toform a perfect, homogeneous road-covering.

Example: About 900 kilograms finely ground lime-stone are equallymoistened and 200 kilograms emulsion of asphalt-

